Propeller



y 1942- C.;N. TAYLOR 2,282,436

PROPELLER Filed Nov. 20, 1939 INVENTOR.

A TTORNEYS.

Q/FF'OED NOE/719A 7/9 VA 06 J Patented May 12, 1942 UNITED STATES PATENTOFFICE 2,282,436 PROPELLER Clifford Norman Taylor, Fargo, N. Dak.,assignor to Outboard, Marine and Manufacturing Company, Waukegan, 11].,a, corporation of Delaware Application November-20, 1939, Serial No.305,246 r 14 Claims. '(01. 170-164 This invention relates toimprovements in propellers with particular reference to marinepropellers.

- vention.

In the drawing:

Fig. l is a rear elevation of a. propeller embodying the invention.

Fig. 2 is a side elevation of the propeller as viewed from the right'ofFig. 1. I,

Fig. 3 is a view taken in section on the line 33 of Fig. 1.

Like parts are identified by the same reference characters throughoutthe'several views.

The hub-5 has the conventional bore 6 and counterbore 1 to receive thepropeller shaft; At

either side of bore 5, the hub is pierced by holes in which the pintlepins 8 'are held by set screws '9 to provide fulcrums for the blades 10.The

portions of the hub 5 through which the pintles 8 extend have fiat sidesH beyond which the I pintles 8 project and against which the arms and I6of the respective blades bear.

The blades ID are identical castings. Each has a. root portionencircling the narrow side of the hub and provided with spaced arms I5and I 6 between which the flattened portion of the hub is received. Ineach case, the trailing edge of the blade is located adjacent theprojected axis of the pintle so that the major portion of the waterengaging face of the blade is located forwardly,

of the pintle and the leading edge is remote from the pintle. The bladeproper has a general direction of extent laterally from its rootelement, the blade center line being obliquely inclined with respect tothe pintle axis as clearly appears in Fig. 1.

As best shown in Fig. 2, the arms of the respective blades havecomplementary cam or tooth portions which interact to require that theblades move in unison about their respective fulcrums. In all positionsof the blades, their complementary arms are loosely nested together andthe contours of their opposed margins are such that in effect each ofthe arms 16 has a tooth at H fitted between rounded teeth l8 and IQ ofthe arm 15 of .the other blade. Consequently, when one blade is rockedfrom the full line position to the dotted line position shown in Fig. 2,the other blade rocks through a corresponding change of angular positionso that at all tim es the two blades have identical pitch adjustments.

In assembling the blades on the hub, compression springs 20 are insertedbetween each blade and a shoulder of the hub as shown in Fig. 3. Thesesprings exert their pressure in a direction to maintain the blades intheposition of minimum pitch ad ustment shown in Fig. 1 and Fig. 2. Thisposition is defined by engagement of the type 2| of arm 16 of one bladewith the rounded tooth [8 of the arm I5 01 the other blade. In,practice, the compression of spring 20 will be sufficient to maintainthe blades in their position of minimum pitch adjustment, whenever themotor which drives the propeller shaft upon which hub 5 is mountedisidling or operating at a predetermined reduced speed. When the speedofthe motor is increased, thereby increasing the torque to which theblades are subject, the fact that the greatest portion of the area ofeach blade is aheadof the pintle 8 will cause the thrust to be exertedon the blade in opposition to spring 20 with the result that whenthetorque is increased to a suflicient value, the blades willsimultaneously move to their position of maximum pitch adjustment asdetermined by the engagement of the end 22 of the arm I 5 of each bladewith the rounded portion 23 of the arm I6 of the other blade. Thepropeller is now adjusted .toa

position for maximum thrust to use the entire power developed by theengine in its higher speed v of operation.

Since the blades are identical, only two castings are required-and thesprings, pintles and set screws are the only parts used in the assembly.The outlines are so streamlined that the propeller is virtually Weedlessin operation.

The intermeshing contours of the tooth portions ,of the respective bladeroot elements are preferably the contours of conventional gear teeth.Because each blade is acted upon individually by its own spring andis-subiect to like conditions of pressure and thrust, these teeth arenot subject to any substantial pressures and mere. y perform aregulating function.

Icla-imi- 1. In a propeller, the combination with a laterally elongatedhub provided with spaced transversely extending pint-1e means adjacentits respective narrow sides, of bifurcated blade root elementsencircling the narrow sides of the hub and provided with interlockingextensions projecting along the wider sides of the hub, compressionsprings interposed between said root elements and the narrow sides ofthe hub and acting on said root elements in a direction to oscillatethem toward a minimum pitch position, and blades carried by therespective elements and projecting therefrom beyond the respective widersides of the hub.

2. In a propeller, the combination with a laterally elongated hubprovided with spaced transversely extending pintle means adjacent itsrespective narrow sides, of bifurcatedblade root elements encircling thenarrow sides of the hub and provided with interlocking extensionsprojecting along the wider sides of the hub, compression springsinterposed between said root elements and the narrow sides of the huband acting on said root elements in a direction to oscillate them towarda minimum pitch position, and blades carried by the respective elementsand projecting therefrom beyond the respective wider sides of the hub,sai'd blades having their major area disposed forwardly in the directionof propeller rotation of the respective pintle axes as extended towardthe tips of the blades, whereby their thrust is opposed to said springmeans to oscillate the blades and root elements toward positions ofmaximum pitch when a predetermined torque is developed.

3. Ina self-feathering propeller; the combination with a. hub, ofbifurcated root elements fulcrumed to the hub and partially encirclingopposite sides thereof, each of said root elements being connected tothe hub at opposite sides movement of the elements on their respectivepintles and tooth surfaces intermeshing to constrain the elements toconcurrent pitch adjustment on said pintles, and blades carried by theperspective root elements for pitch adjustment thereof, and bladesextending obliquely from the a respective root elements and havingtrailing edges near the axes on which the root elements are fulcrumed tothe hub, and leading edges remote from said axes in the direction ofpropeller rotation, the axes upon which the root elements are fulcrumedbeing approximately centered with reference to the hub and laterallyoffset therefrom.

4. In a propeller, the combination with a hub having a central mountingbore and transverse pintles spaced at opposite sides thereof, of bladeroot elementspartially encircling the hub andv having arms pivoted onthe respective pintles and provided with directly interacting andmutually interlocking terminal portions having stop surfaces limitingthe movement of the elements on their respective pintles and toothsurfaces directly intermeshing with each other to constrain the elementsto concurrent pitch adjustment on said pintles, and blades carried bythe perspective root elements for pitch adjustment in the movement ofsaid elements on said pintles.

5. In a propeller, the combination with a hub having a central mountingbore and transverse pintles spaced at opposite sides thereof, of bladeroot elements partially encircling the hub and having arms pivoted onthe respective pintles and provided with mutually interlocking terminalportions having stop surfaces limiting the movement of the elements ontheir respective pintles and tooth surfaces intermeshing to constrainthe elements to concurrent pitch adjust ment on said pintles, and bladescarried by the perspective root elements for pitch adjustment in themovement of said elements on said pintles, together with spring meansinterposed between the hub and the respective elements and biasing saidelements and blades toward positions of minimum pitch.

in the movement of said elements on said pintles, together with springmeans interposed between the hub and the respective elements and biasingsaid elements and blades toward positions of minimum pitch said bladesextending obliquely from the respective elements in opposite directionsand provided with trailing edges lying near the projected axes of therespective pinties and with leading edges remote from said projectedaxes in the direction of propeller rotation whereby the major portion ofthe area of each blade is disposed forward of 'its axis of pitchadjustment and its thrust is opposed to said spring means.

'I. In a propeller, the combination with a hub, of a plurality of bladeshaving bifurcated arm portions at their roots partially encircling thehub and from which the respective blades project obliquely, meanspivotally connecting the arm portions of each blade individually to thehub, said arm portions of the respectiveblades overlapping at oppositesides of the hub and being provided with gear tooth surfacesin' opof aplurality of blades, means pivotallyconnecting the blades to the hub forfeathering adjustment thereon, and arms rigidly projecting from therespective blades beyond their points of respective pivotal connectionwith the hub and provided with complementary intermeshing means adaptedfor the direct transmission. of motion between the 'arms of therespective blades for maintaining said blades in synchronism as to theirchange of pitch adjustment.

19. In a propeller, the combination with a hub, of a plurality ofidentical blades provided individually with pivotal connections to thehub upon which said blades are adapted to move for pitch adjustment,each of said identical blades being provided with first and second armsspaced to embrace the hub and projecting beyond the pivotal connectionof the respective blade's with the hub, the first arm of each bladehaving a toothed portion and the second arm of each blade having acomplementarily toothed portion and the toothed portion of the first armof each blade being directly intermeshed with the complementary toothedportion of the second arm of another blade, whereby the several bladesare interconnected for concurrent pitch adjustment.

10. In a propeller, the combination with a hub having opposed sidebearing portions and a shaft socket therebetween, of pintle meansprojecting from said bearing portions at each side of said shaft socket,blades having bifurcated root portions fulcrumed on the respectivepintle means and embracing said hub in operative bearing engagement withthe opposed bearing surfaces thereof, said blades projecting obliquelyfrom their bifurcated root portions, each of the biiurcated rootportions of the respective blades bearing teeth and the teeth of saidblade root portions being directly intermeshed with each other at eachside of said hub, whereby said blades are directly intergeared forconcurrent movement about the respective pintle means.

11. In a propeller, the combination with a hub having opposedsidebearing portions and a shaft socket therebetween, of pintle meansprojecting from said bearing portions at each side of said shaft socket,blades having bifurcated root portions fulcrummed on the respectivepintle means and embracing said hub in operative bearing engagement withthe opposed bearing surfaces thereof, said blades projecting obliquelyfrom their bifurcated root portions, each of the bifurcated rootportions of the respective blades bearing teeth and the teeth of saidblade root portions being directly inter-meshed with each other at eachside of said hub, whereby said blades are directly inte'rgeared forconcurrent movement about the respective pintle means, the bifurcatedroot portions of the'respective blades being convexly arranged andcomplementary to build out the sides of the propeller hub beyond thebearing surfaces thereof, whereby to provide a substantially continuous.and smooth weed shedding surface.

12. A propeller comprising the combination with a hub havinga shaftopening upon the axis of which said hub is rotatable, of blade fulcrummeans having axes substantially parallel to each other and laterallyoffset and approximately centered at opposite sides of said shaftopening,

and substantially identical blade members pivoted upon the respectivefulcrum means and extending obliquely at an acute angle to the axes:

axis of which said hub is rotatable, of blade fulcrum means having axessubstantially parallel to each other at opposite sides of said shaftopening, of substantially identical blade members pivoted upon therespective fulcrum means and extending obliquely at an acute angle tothe axes of the respective fulcrum means forwardly of such axes in thedirection of hub rotation, whereby to be adapted for pitch adjustmentupon the respective'fulcrum means,

said blade members having blade root elements disposed laterallyadjacent the hub between the respective fulcrum means at each side ofthe hub, and having directly intermeshing toothed portions constrainingsaid blades to like pitch changing movement upon their respectivefulcrum means. 7

14. A propeller comprising the combination with a hub having a centralopening on the axis of which said hub is rotatable, said hub beingprovided with bearing faces laterally adjacent the opening and withpintle means at different sides of said opening projecting from therespective bearing faces, of identical bifurcated blade members, eachprovided at its root portion with spaced arms bearing on the bearingfaces of the hub, each of said blades projecting obliquely from its saidroot portion at an acute angle to the respective pintle means upon whichit is fulcrummed, the respective blades being adjustable as to pitchabout their respective fulcrum means between predetermined minimum andmaximum pitch positions. means on the arms of the respective bladesintermeshing with each other whereby the pitch adjusting movement of theseveral blades is concurrent, means limiting such pitch adjustingmovement, and means biasing the several blades toward said minimum pitchpositions, said blades having major por.- tions disposed forwardly oftheir respective axes of pitch adjustment upon said pintle means, thepressure of said biasing means being such that said blades under loadare adapted to overcome said biasing means and move automatically andconcurrently to said maximum pitch positions. CLIFFORD NORMAN TAYLOR.

